Built a fairly large Flash Catalyst project and have exported and saved it many times over in the past with no problems. I forget what I tweaked a few days ago when I last saved this project, but I went to open it today, it's giving me a huge list of Unexpected errors:

I have no idea what this means. I tried importing this project into Flash Builder like another forum said to do and locate these lines, but I don't know how to actually get to the lines area in Flash Builder.

Once you have done that then, we can try locating the issue. Go Project > Flash Catalyst > Import Flash Catalyst Compatibile Project.

You use the Project Explorer on the left side of the interface to access the files that make up the project. We want to open [project name] > src > (default package) > Main.mxml. Double click on Main.mxml to open it in the editor. To enable the line numbers, right click on the left side of the editor.

Now you can go in and find the offending lines. Without seeing the code and can't advise further. You might be best served to try to remove it all together, and then return to Catalyst.

Also I would recommend adding a backup (aka version control) element to your workflow.